Significant individual differences in HIV progression suggest that psychoneuroimmunological (PNI) mechanisms are implicated. Previous and preliminary studies by the investigators have demonstrated a longitudinal relationship between the maladaptive Type C coping style (emotionally inexpressive, not recognizing own needs or feelings) and HIV progression;and a cross-sectional relationship between Type C coping and lower production of HIV-specific beta chemokines, which are ligands for the CCR5 HIV coreceptor, and associated with potent HIV inhibitory activity. The purpose of the proposed study is to test within a single longitudinal study the hypothesis that higher levels of Type C coping contribute to HIV progression through dysregulation of HIV -specific beta-chemokine production. Biopsychosocial assessments of at least 100 HIV-infected participants will be conducted at baseline (starting with N = 200 to address expected attrition, and at 6, 12, 18, 24, and 36 months on psychosocial measures, including Type C coping;psychophysiological measures of stress and reactivity;laboratory measures of beta-chemokines and cytokines for which there is evidence or theoretical rationale for their relevance to HIV progression;and clinical variables including CD4 cell count, HIV-1 RNA (viral load, VL). Medical status only assessed will be determined at 48 months. Multivariate analyses will examine the contribution of these measures and their interactions to elucidate potential mediators of HIV progression, controlling for baseline clinical status and antiretroviral therapy. The goal is to understand and delineate how observed relationships and interactions among biopsychosocial factors may contribute to HIV progression through such "macro-mediators" as deregulation in homeostatic control, which have been demonstrated or hypothesized to be related to HIV progression.